It will take your bullet .098 seconds to reach the target 40 yards away. 25 mph equals 36.7 fps. The coyote will travel about 3.6 feet by the time the bullet reaches it. If you hold 3 feet in front of the tip of his nose you should hit him in the ear. 00 buckshot would be the way to go.

Looking back 40 years to high school calculus there is an equation for this. we had an algorithm to compensate for deceleration of ammo. But you can figure it out with simple math by collecting the data for ammo speed at 40 yds. You already know that muzzle speed is 1225, then use the 40 yd velocity to find the average velocity over the entire 40 yds. Easy if you have the data.